1. Field of Invention
This invention relates to a system for treating web material such as paper sheets, and in particular, to a system that substantially simultaneously bulks, crepes, embosses and provides extensibility thereto and locks said characteristics into the web material.
2. Description of the Prior Art
A number of systems have been employed in the past for bulking, creping and embossing paper webs and similar web material to attain desirable characteristics in the end product such as extensibility, greater absorbency and strength and higher bulk. Such prior art approaches are generally characterized by their complexity and high expense and the process steps are often carried out sequentially through the use of separate equipment between which the web must be conveyed across open draws. Open draws lead to web control problems which may place unnecessary speed limitations on the production equipment to avoid web breakage or other undesirable consequences. It is often desirable to perform such treatment on paper webs still sufficiently wet so that the cellulosic fibers thereof have not yet been completely bonded together or set and the problem of potential web breakage becomes even more acute. Also, when conveying a web in moist condition between the various operating stages there is always some loss of the characteristics imparted to the web at the previous stage or stages. For example, in a wet web loss of crepe is frequently encountered after the wet creping stage because of the weakness thereof, particularly when the sheet is passed through an open draw as is often the case in conventional wet creping operations.